Epileptic patients who are refractory to anticonvulsant medications.

To evaluate criteria that predict success or failure of currently available anticonvulsant medications, we studied 194 epileptic patients who were admitted to an intensive treatment unit. Seizures were present in the hospital in 78.3% and could not be controlled in 33.7%. Combinations of at least two of the following criteria were associated with limited treatment responses: multiple handicap (intellectual limitations or abnormal neurologic signs), different seizure types, cluster seizures, slowing of EEG background rhythms, and seizures discharges in the EEG despite adequate anticonvulsant blood levels. Presumed etiology was not associated with predictive ability. Patients who were neurologically and intellectually intact and had frequent clinical attacks, normal EEG background rhythms, and no seizure discharges usually had pseudoseizures.